Spring-holder for flasks.



No. 684,253. Patented Oct. 8, |9o|.'

.1. n. HOUSTON.

SPRING HOLDER FOR FLASKS.

(Apphcahon filed N UNITED STATES PATENT OFFICE.

JAMES D. HOUSTON, OF NEBRASKA CITY, NEBRASKA.

SFRING-HOLDER FOR FLASKS.

srsorrrcecrron forming part of Letters Patent No. 684,253, dated Octobers, 1901. Application filed November 21, 1900. Serial l lo. 37,227. (Nbmodel.)

To ctZZ 1071,0712, it may concern:

Be it known that I, JAMES D. HOUSTON, a citizen of the United States,residing at Nebraska City, in the county of Otoe and State of Nebraska,have invented a new and useful Improvement in Spring-Holders for Flasks,of which the following is a specification.

My invention relates to improvements in spring-holders for flasks usedby dentists in making artificial dentures or teeth, and moreparticularly to that class of flasks which are designed to be automaticin operation by means of springs or similar devices applied to theseveral parts of the flask and which are designed to automatically closethe several parts when the rubber contained therein has been reduced toa plastic state.

The primary object of my invention is to produce an improved device forthis purpose which will be simple in construction and efficient inoperation.

lVith this end in view the invention consists, essentially, of anautomatic flaskspring, substantially as shown in the accompanyingdrawings and hereinafter more fully described, and particularly pointedout in the appended claims.

In the drawings forming a part of this specification, Figure 1 is a sideelevation of a flask provided with my flask-springs and illustrating theseveral parts in their operative position. Fig. 2 is a similar viewshowing the position of the parts after the springs have performed theirfunction. Fig. 3 is a plan view of the spreading-pliers for applying thesprings to the flask, with a sectional View of the spring, illustratingthe manner in which it is inserted in the pliers. Fig. 4 is a detailperspective View of the spring.

Referring to the drawings, A designates the spring, formed of acontinuous piece of metal and consisting of a main body portion a, whichis preferably slightly curved, as shown, and bent intermediate themiddle and end portions thereof into substantially semicylindricalshape, forming two spring-arms Z2. After being bent to form theoppositely-disposed spring-arms b the ends are each bent to form loopsor hooks a the purposes of which will be hereinafter explained.

The manner of attaching the springs to the flask is as follows: Theflask is first supplied with the requisite amount of rubber and'thcparts are placed in proper position, as shown in Fig. 1. The tips of thejaws of a pair of spreading-pliers D are then inserted into the loops orhooks a of the spring, as shown in Fig. 3, and the oppositely-disposedspring arms I) are then sprung outwardly, thus increasing theintervening space between the tips of the spring-arms. The spring isthen applied to the flask B, in the manner shown in Fig. 1, by means ofthe spreading-pliers and released and the pliers removed. It willtherefore be apparent that the oppositelydisposed spring-arms b of thesprings will exert a strong inward pressure to the several parts of theflask B and that when the same has been placed in the vulcanizer and therubber contained therein has been reduced to a plastic condition theseveral parts will be automatically forced together and the edges of thesame firmly united, as shown in Fig. 2.

Heretofore in place of my automatic flasksprings bolts were used and theflask placed in boiling water for several minutes and removed, the boltsscrewed down only a little at a time, and the flask replaced in water asbefore, and so on until the edges of the several parts of the flask werebrought together, after which it was placed in a vulcanizer and allowedto heat to 320 and remain for a time in order to harden the rubber. Itwill be readily seen that this process requires considerable time andlabor. With a flask equipped with my automatic flask-springs thisprocess is rendered unnecessary, and one has simply to pack rubber inthe flask, place the springs in the position shown in Fig. 1, and placethe whole case in the vulcanizer at once. As the temperature rises to280 the rubber becomes plastic and the springs automatically close downand bring the edges of the several parts of the flask together, as shownin Fig. 2, thereby molding the rubber to the form of the model inside.

The operation and advantages of my invention will be manifest to thoseversed in the character of Work to which it appertains, and numerousmodifications may be made without departing from the spirit and scope ofmy invention.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is-

1. A spring for flasks, the same consisting of a continuous piece ofmetal bent to form a slightly-curved main body portion, and then bent,midway between its middle and ends, into s ubstantially semieylindricalshape forming oppositely-disposed spring-arms, and having their freeends bent outwardly to form loops or hooks adapted to receive the tipsof the jaws of a pair of spreading-pliers whereby the said spring-armsmay be sprung outwardly when the spring is placed upon the flask,substantially as shown and for the purpose set forth.

2. In a spring for flasks, a continuous piece of metal bent to form acurved main body por-

